Prostate 3T-MR spectroscopic imaging without an endorectal surface coil using the MLEV-PRESS sequence.

PURPOSE: The aim of this study was to determine to what extent we could identify the metabolism product peak using 3-T proton magnetic resonance spectroscopic imaging (MRSI) of the prostate gland in healthy volunteers by combining an external array coil with Malcolm Levitt composite-pulse decoupling sequence (MLEV)-point-resolved spatially localized spectroscopy (PRESS). MATERIALS AND METHODS: MRSI data were obtained from the entire prostate gland in six healthy volunteers. The heights of the choline, citrate peaks and the standard deviation (SD) of the noise in each voxel were calculated. When the choline and/or citrate peak in a voxel exceeded 3 SD, the peak was clearly identified. RESULTS: The clear citrate peak rate in the peripheral zone (PZ) and the central gland (CG) were 78.8 and 70.3 %, respectively. The clear choline peak rate in the PZ and the CG were 55.4 and 44.9 %, respectively. In addition, the clear peak rates for both citrate and choline in the PZ and the CG were 51.8 and 38.6 %. Therefore, in the entire prostate gland, 75.2 % had a clear citrate peak, 51.1 % had a clear choline peak, and 46.3 % had both citrate and choline peaks. CONCLUSION: The citrate peak was clearly detected in 75.2 % of the voxels by this technique.

Equivalent cross-relaxation rate imaging for sentinel lymph node biopsy in breast carcinoma.

Sentinel lymph node biopsy (SLNB) is an important technique for detecting axillary lymph node metastasis in breast carcinoma patients. However, false-negative results are a problem. Equivalent cross-relaxation rate (ECR) imaging (ECRI) is a measurement method that can be used to quantitatively evaluate a change in the structural organization of lymph nodes by magnetic resonance imaging (MRI). We performed axillary ECRI in an attempt to decrease the false-negative results of SLNB. Regions without metastases showed a higher ECR value. On the other hand, regions with metastases showed a lower ECR value. The ECR images were compared with macroscopic histology images in which the presence or absence of axillary lymph node metastasis could be evaluated. ECRI is a potentially useful method for evaluating the efficacy of SLNB.

[Usefulness of lower extremity 2D TOF MR venography with respiratory compensation technique, and effect of patient positioning on the visualization of deep veins in the leg].

We evaluated the usefulness of two-dimensional time-of-flight (2D TOF) MR venography (MRV) of the lower extremity using the respiratory compensation (RC) technique. In addition, six variations in patient positioning of the leg and knee were investigated to determine the best method of visualizing the deep popliteal veins and lower leg. All data sets were reviewed and graded for visualization of the deep veins at the pelvis, thigh, and leg portion (4-point scale) by two radiologists and three radiological technologists. The same veins demonstrated with various positions of the patient were also evaluated in the same manner. In conclusion, 2D TOF MRV with RC resulted in increased uniformity of vein signal in the pelvic area. Furthermore, we should position the patient's leg so as not to compress the vein at the posterior portion of the leg, and not to over-extend the knee joint. This enabled the best results to be obtained in MRV of the lower extremity.